Rory McIlroy has employed only two caddies in his professional career - Gordon Faulkner and JP Fitzgerald.

Faulkner, who caddied at Queensway GC in Surrey, was recommended to McIlroy by Darren Clarke. He carried McIlroy's bag in the 2007 Walker Cup after which the Holywood GC member turned professional, but their relationship lasted less than a year.

By the summer of 2008, the fledgling professional found himself struggling to adjust to life on the road, and the loneliness that comes with an adjustment from the team environment of top level amateur golf. His then manager, Chubby Chandler, the top man at International Sports Management, has been credited with suggesting that Fitzgerald come on board.

The former single-figure amateur had played in the 1987 and 1992 Irish Close championship, reaching the final both years, but losing to Eddie Power and Gary Murphy respectively.

Fitzgerald attended East Tennessee State University on a scholarship, and when he returned to Ireland was offered his first caddie job with Paul McGinley in 1995.

The County Louth GC member worked with McGinley until 2003, and after that had spells with Clarke, Greg Owen and Ernie Els before he came on board with McIlroy.

Their first event together was in the 2008 SAS Masters in August. Missed cut. Next event, the KLM Open, missed cut. Third event, Johnnie Walker Championship - missed cut.

Not an auspicious beginning, but finally McIlroy had a breakthrough and got beaten in a play-off for the Omega Masters in Switzerland.

At that stage, McIlroy was 210th in the world rankings, but by the end of 2008, the Northern Irishman was 40th and well on his way to fulfilling the potential he had shown as a top-class amateur.

The Irish North-South partnership earned their first victory in February 2009, at the Dubai Desert Classic.

The golfer was just 19 and the victory proved to be a launchpad for what has already been a stellar career by any standards.

Since then they have gone on to win 20 tournaments, including four Majors, and seen McIlroy reach the world number one position.

Through it all, Fitzgerald remained the 'quiet man' who has shunned publicity and done his job diligently.

The man from Castleknock in Dublin is known to his friends for his brand of dry humour but when on duty, preferred to stay in the background and do the job that McIlroy paid him to do.

Fitzgerald never complained about the criticism that came his way from American commentator Jay Townsend at the 2011 Irish Open in Killarney, or about other gripes.

Townsend, a former pro, had a go at the caddie's performance on social media, saying: "JP (Fitzgerald) allowed some SHOCKING course management today." McIlroy blasted back, also on Twitter: "You're a commentator and a failed golfer, your opinion means nothing."

That led to a right royal row and calls for McIlroy to apologise.

"He's been having a go at JP every now and again since then and this was the first time I've responded - it was the straw that broke the camel's back," said McIlroy, who also blocked Townsend on Twitter.

Through all the ups and downs over the last nine years, overall the two men prospered in a big way.

Financially, Fitzgerald hit the jackpot in his chosen career.

McIlroy's total prize money from the PGA Tour and European Tour totals around €64 million, and with bonuses and percentages, the caddie's gross earnings from the job are estimated to be around €7 million.